Quantum Systems Defy Freezing Logic

Researchers investigated the Mpemba effect in quantum systems, a phenomenon where hotter water can freeze faster than cooler water. This quantum Mpemba effect retains memory of its initial conditions, affecting its thermal relaxation later. The team used two systems with quantum dots and discovered the thermal quantum Mpemba effect across various conditions, suggesting possible broader applications beyond thermal analysis.



Hotter quantum systems can cool faster than initially colder equivalents.

Does hot water freeze faster than cold water? Aristotle may have been the first to tackle this question that later became known as the Mpemba effect.

This phenomenon originally referred to the non-monotonic initial temperature dependence of the freezing start time, but it has been observed in various systems — including colloids — and has also become known as a mysterious relaxation phenomenon that depends on initial conditions.

What Is the Mpemba Effect?
The Mpemba effect is a counterintuitive phenomenon where hot water can freeze faster than cold water under certain conditions. Named after Erasto Mpemba, a Tanzanian student who observed this effect in the 1960s and subsequently brought it to the attention of the scientific community, the phenomenon has been a topic of curiosity for centuries, with references dating back to the likes of Aristotle. The exact cause of the Mpemba effect is still a topic of debate among scientists.

Recent Findings
Now, a team of researchers from Kyoto University and the Tokyo University of Agriculture and Technology has shown that the temperature quantum Mpemba effect can be realized over a wide range of initial conditions.

“The quantum Mpemba effect bears the memory of initial conditions that result in anomalous thermal relaxation at later times,” explains project leader and co-author Hisao Hayakawa at KyotoU’s Yukawa Institute for Theoretical Physics.  READ MORE...